If you've read any of the books, you'll know this: Jack Reacher is a seriously big guy. He's 6'5", weighs in at 250lbs and has a 50 inch chest. Reacher's face is plain to the point of being nearly ugly.
Tom Cruise is ten inches shorter (even when he's wearing
Reacher is big enough to have deliberately taken a .38 Special slug in the chest and then beaten the shooter to death. You could probably drop Tom Cruise with a single shot to the chest from a .25 ACP.*
Even Ashton Kucher would be better, for at least he's reasonably tall. Jack Reacher doesn't exactly have a wide emotional range; there are at least half-a-dozen guys in the WWF who, with a little bit of acting training, could pull it off.** There are at least two or three times that many in the NFL. About the only way to cast the role of Jack Reacher worse would be to have Katherine Heigl play the part.***
I'm not a big fan of the Jack Reacher series. After a few, they seemed to be cookie-cutter books that can be read the same way as a Louis L'Amour western: Read the first chapter, the last chapter and five random pages inbetween.
But I don't see how a Reacher fan could watch this movie without either laughing uproariously or stalking out in seething anger.
* As Jeff Cooper supposedly said about having a .25: "Don't load it. If you load it, you might shoot it, and if you shoot it, you might hit someone. If you hit someone, they will be very, very mad at you."
** They already know how to act a litle.
*** Heigl could probably handle the emotional range. Maybe.